+extern const unsigned char tls13_aes128gcmsha256_id[];
+extern const unsigned char tls13_aes256gcmsha384_id[];
+extern BIO_ADDR *ourpeer;
+
+BIO_METHOD *apps_bf_prefix(void);
+/*
+ * The control used to set the prefix with BIO_ctrl()
+ * We make it high enough so the chance of ever clashing with the BIO library
+ * remains unlikely for the foreseeable future and beyond.
+ */
+#define PREFIX_CTRL_SET_PREFIX (1 << 15)
+/*
+ * apps_bf_prefix() returns a dynamically created BIO_METHOD, which we
+ * need to destroy at some point. When created internally, it's stored
+ * in an internal pointer which can be freed with the following function
+ */
+void destroy_prefix_method(void);
+